/*
 * lfs utility functions
 *
 * Copyright (c) 2017, Arm Limited. All rights reserved.
 * SPDX-License-Identifier: BSD-3-Clause
 */
#ifndef LFS_UTIL_H
#define LFS_UTIL_H

// Users can override lfs_util.h with their own configuration by defining
// LFS_CONFIG as a header file to include (-DLFS_CONFIG=lfs_config.h).
//
// If LFS_CONFIG is used, none of the default utils will be emitted and must be
// provided by the config file. To start, I would suggest copying lfs_util.h
// and modifying as needed.
#ifdef LFS_CONFIG
#define LFS_STRINGIZE(x) LFS_STRINGIZE2(x)
#define LFS_STRINGIZE2(x) #x
#include LFS_STRINGIZE(LFS_CONFIG)
#else

// System includes
#include <inttypes.h>
#include <stdbool.h>
#include <stdint.h>
#include <string.h>


//#define LFS_NO_MALLOC
#define LFS_NO_ASSERT
#define LFS_NO_DEBUG
#define LFS_NO_WARN
#define LFS_NO_ERROR
#define LFS_NO_INTRINSICS
//#define LFS_YES_TRACE

#ifndef LFS_NO_MALLOC
#include <stdlib.h>
#endif
#ifndef LFS_NO_ASSERT
#include <assert.h>
#endif
#if !defined(LFS_NO_DEBUG) || !defined(LFS_NO_WARN) || !defined(LFS_NO_ERROR) || defined(LFS_YES_TRACE)
#include <stdio.h>
#endif

#ifdef __cplusplus
extern "C" {
#endif


// Macros, may be replaced by system specific wrappers. Arguments to these
// macros must not have side-effects as the macros can be removed for a smaller
// code footprint

// Logging functions
#ifdef LFS_YES_TRACE
#define LFS_TRACE_(fmt, ...) printf("%s:%d:trace: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
#define LFS_TRACE(...) LFS_TRACE_(__VA_ARGS__, "")
#else
#define LFS_TRACE(...)
#endif

#ifndef LFS_NO_DEBUG
#define LFS_DEBUG_(fmt, ...) printf("%s:%d:debug: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
#define LFS_DEBUG(...) LFS_DEBUG_(__VA_ARGS__, "")
#else
#define LFS_DEBUG(...)
#endif

#ifndef LFS_NO_WARN
#define LFS_WARN_(fmt, ...) printf("%s:%d:warn: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
#define LFS_WARN(...) LFS_WARN_(__VA_ARGS__, "")
#else
#define LFS_WARN(...)
#endif

#ifndef LFS_NO_ERROR
#define LFS_ERROR_(fmt, ...) printf("%s:%d:error: " fmt "%s\n", __FILE__, __LINE__, __VA_ARGS__)
#define LFS_ERROR(...) LFS_ERROR_(__VA_ARGS__, "")
#else
#define LFS_ERROR(...)
#endif

// Runtime assertions
#ifndef LFS_NO_ASSERT
#define LFS_ASSERT(test) assert(test)
#else
#define LFS_ASSERT(test)
#endif


// Builtin functions, these may be replaced by more efficient
// toolchain-specific implementations. LFS_NO_INTRINSICS falls back to a more
// expensive basic C implementation for debugging purposes

// Min/max functions for unsigned 32-bit numbers
static inline uint32_t lfs_max(uint32_t a, uint32_t b)
{
	return (a > b) ? a : b;
}

static inline uint32_t lfs_min(uint32_t a, uint32_t b)
{
	return (a < b) ? a : b;
}

// Align to nearest multiple of a size
static inline uint32_t lfs_aligndown(uint32_t a, uint32_t alignment)
{
	return a - (a % alignment);
}

static inline uint32_t lfs_alignup(uint32_t a, uint32_t alignment)
{
	return lfs_aligndown(a + alignment - 1, alignment);
}

// Find the smallest power of 2 greater than or equal to a
static inline uint32_t lfs_npw2(uint32_t a)
{
#if !defined(LFS_NO_INTRINSICS) && (defined(__GNUC__) || defined(__CC_ARM))
	return 32 - __builtin_clz(a - 1);
#else
	uint32_t r = 0;
	uint32_t s;
	a -= 1;
	s = (a > 0xffff) << 4;
	a >>= s;
	r |= s;
	s = (a > 0xff) << 3;
	a >>= s;
	r |= s;
	s = (a > 0xf) << 2;
	a >>= s;
	r |= s;
	s = (a > 0x3) << 1;
	a >>= s;
	r |= s;
	return (r | (a >> 1)) + 1;
#endif
}

// Count the number of trailing binary zeros in a
// lfs_ctz(0) may be undefined
static inline uint32_t lfs_ctz(uint32_t a)
{
#if !defined(LFS_NO_INTRINSICS) && defined(__GNUC__)
	return __builtin_ctz(a);
#else
	return lfs_npw2((a & -a) + 1) - 1;
#endif
}

// Count the number of binary ones in a
static inline uint32_t lfs_popc(uint32_t a)
{
#if !defined(LFS_NO_INTRINSICS) && (defined(__GNUC__) || defined(__CC_ARM))
	return __builtin_popcount(a);
#else
	a = a - ((a >> 1) & 0x55555555);
	a = (a & 0x33333333) + ((a >> 2) & 0x33333333);
	return (((a + (a >> 4)) & 0xf0f0f0f) * 0x1010101) >> 24;
#endif
}

// Find the sequence comparison of a and b, this is the distance
// between a and b ignoring overflow
static inline int lfs_scmp(uint32_t a, uint32_t b)
{
	return (int)(unsigned)(a - b);
}

// Convert between 32-bit little-endian and native order
static inline uint32_t lfs_fromle32(uint32_t a)
{
#if !defined(LFS_NO_INTRINSICS)                                                                               \
	&& ((defined(BYTE_ORDER) && defined(ORDER_LITTLE_ENDIAN) && BYTE_ORDER == ORDER_LITTLE_ENDIAN)            \
		|| (defined(__BYTE_ORDER) && defined(__ORDER_LITTLE_ENDIAN) && __BYTE_ORDER == __ORDER_LITTLE_ENDIAN) \
		|| (defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__))
	return a;
#elif !defined(LFS_NO_INTRINSICS)                                                                       \
	&& ((defined(BYTE_ORDER) && defined(ORDER_BIG_ENDIAN) && BYTE_ORDER == ORDER_BIG_ENDIAN)            \
		|| (defined(__BYTE_ORDER) && defined(__ORDER_BIG_ENDIAN) && __BYTE_ORDER == __ORDER_BIG_ENDIAN) \
		|| (defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))
	return __builtin_bswap32(a);
#else
	return (((uint8_t *)&a)[0] << 0) | (((uint8_t *)&a)[1] << 8) | (((uint8_t *)&a)[2] << 16)
		   | (((uint8_t *)&a)[3] << 24);
#endif
}

static inline uint32_t lfs_tole32(uint32_t a)
{
	return lfs_fromle32(a);
}

// Convert between 32-bit big-endian and native order
static inline uint32_t lfs_frombe32(uint32_t a)
{
#if !defined(LFS_NO_INTRINSICS)                                                                               \
	&& ((defined(BYTE_ORDER) && defined(ORDER_LITTLE_ENDIAN) && BYTE_ORDER == ORDER_LITTLE_ENDIAN)            \
		|| (defined(__BYTE_ORDER) && defined(__ORDER_LITTLE_ENDIAN) && __BYTE_ORDER == __ORDER_LITTLE_ENDIAN) \
		|| (defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__))
	return __builtin_bswap32(a);
#elif !defined(LFS_NO_INTRINSICS)                                                                       \
	&& ((defined(BYTE_ORDER) && defined(ORDER_BIG_ENDIAN) && BYTE_ORDER == ORDER_BIG_ENDIAN)            \
		|| (defined(__BYTE_ORDER) && defined(__ORDER_BIG_ENDIAN) && __BYTE_ORDER == __ORDER_BIG_ENDIAN) \
		|| (defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__))
	return a;
#else
	return (((uint8_t *)&a)[0] << 24) | (((uint8_t *)&a)[1] << 16) | (((uint8_t *)&a)[2] << 8)
		   | (((uint8_t *)&a)[3] << 0);
#endif
}

static inline uint32_t lfs_tobe32(uint32_t a)
{
	return lfs_frombe32(a);
}

// Calculate CRC-32 with polynomial = 0x04c11db7
uint32_t lfs_crc(uint32_t crc, const void *buffer, size_t size);

// Allocate memory, only used if buffers are not provided to littlefs
// Note, memory must be 64-bit aligned
static inline void *lfs_malloc(size_t size)
{
#ifndef LFS_NO_MALLOC
	return malloc(size);
#else
	(void)size;
	return NULL;
#endif
}

// Deallocate memory, only used if buffers are not provided to littlefs
static inline void lfs_free(void *p)
{
#ifndef LFS_NO_MALLOC
	free(p);
#else
	(void)p;
#endif
}


#ifdef __cplusplus
} /* extern "C" */
#endif

#endif
#endif
